WASHINGTON — Republicans said Sunday they intend to press Health and Human Services Secretary Kathleen Sebelius on the Obama administration’s troubled launch of healthcare.gov, the online portal to buy insurance, and concerns about the privacy of information that applicants submit under the new system.

The Obama administration will face intense pressure next week to be more forthcoming about how many people have actually succeeded in enrolling for coverage in the new insurance markets. Medicare chief Marilyn Tavenner is to testify during a House hearing on Tuesday, followed Wednesday by Sebelius before the House Energy and Commerce Committee. The officials will also be grilled on how such crippling technical problems could have gone undetected prior to the website’s Oct. 1 launch.

“The incompetence in building this website is staggering,” said Rep. Marsha Blackburn, R-Tenn, the second ranking Republican on the panel.

Democrats said the new system needed time to get up and running, and it could be fixed to provide millions of people with affordable insurance. Kentucky Gov. Steve Beshear, a Democrat, said the system was “working in Kentucky,” a state that has dealt with “some of the worst health statistics in the country ... The only way we’re going to get ourselves out of the ditch is some transformational tool,” like the new health insurance system.

Blackburn said she wanted to know much has been spent on the website, how much more it will cost to fix the problems, when everything will be ready and what people should expect to see on the site. Blackburn and Rep. Mike Rogers, R-Mich., raised questions of whether the website could guard the privacy of applicants.

“The way the system is designed it is not secure,” said Rogers, who is chairman of the House Intelligence Committee.

The botched rollout has led to calls on Capitol Hill for a delay of penalties for those remaining uninsured. The Obama administration has said it’s willing to extend the grace period until Mar. 31, the end of open enrollment. That’s an extra six weeks. The insurance industry says going beyond that risks undermining the new system by giving younger, healthier people a pass.

Sen. Joe Manchin, D-W.Va., who is seeking a yearlong delay to the penalty for noncompliance, said his approach would “still induce people to get involved, but it will also give us the time to transition in. And I think we need that transition period to work out the things.”

The administration was under no legal requirement to launch the website Oct 1. Sebelius, who designated her department’s Medicare agency to implement the health care law, had the discretion to set open enrollment dates. Officials could have postponed open enrollment by a month, or they could have phased in access to the website.

But all through last summer and into early fall, the administration insisted it was ready to go live in all 50 states on Oct. 1.

The online insurance markets are supposed to be the portal to coverage for people who do not have access to a health plan through their jobs. The health care law offers middle-class people a choice of private insurance plans, made more affordable through new tax credits. Low-income people will be steered to Medicaid in states that agree to expand that safety net program.

An HHS memo prepared for Sebelius in September estimated that nearly 500,000 people would enroll for coverage in the marketplaces during October, their first month of operation. The actual number is likely to be only a fraction of that. The administration has said 700,000 people have completed applications.

Blackburn spoke to “Fox News Sunday,” Beshear appeared on NBC’s “Meet the Press,” Rogers was on to CNN’s “State of the Union” and Manchin made his comments on ABC’s “This Week.”